A power conversion apparatus such as an inverter mounted on, for example, a vehicle includes a sensor for measuring a physical quantity of, for example, temperature or voltage and a sensor circuit for adjusting a sensor output to a required measurement range and protection control for the power conversion apparatus is performed on the basis of the output from the sensor circuit. Thus, a faulty output characteristic of the sensor circuit disables proper protection control for the power conversion apparatus.
A known approach toward fault detection of the sensor circuit is to connect a temperature sensor with a ground via a resistance element and a temperature sensor circuit is diagnosed for a fault on the basis of the output from the temperature sensor circuit (PTL 1).